Better water physics, world gen, adjustable speed - v0.1.1

Happy 2021 everyone! Since the holiday break I've been hard at work on the next major feature addition, but there's still quite a ways to go. Look forward to the first major update since PROCJAM in the next several weeks! In the mean time, I've added some nice-to-haves and exposed some more settings to the player. Changes are as follows:

- More variety has been added to random world generation
In addition to the existing fractional brownian motion based heightmap generation, an extra step that warps the domain has been added with a 2/3rds chance of triggering. There's still a ton of work to be done with improving random generation (I could spend a year on this part alone), and there's still a pretty high proportion of both boring and overly extreme landscapes being generated, so for the time being I've set every 1st planet generated per session to the same nice looking preset. I've also decided to make the initial sea level not entirely flat so that the fluid simulation is always demonstrated from the get-go.

- Water viscosity has been halved and default brush strength increased
This was a big improvement in terms of game feel, the water is now feeling a lot more fun to play with right out of the box compared to the game jam version where you had to crank the brush strength up to maximum to get a similar effect.

- Number of simulation steps per frame can now be set, from 0x to 4x (default 3x)
You can now pause the simulation and make whatever changes you want before resuming, which should make for some fun experimentation. Running a lower number of simulation steps may also help performance on lower end systems.

- Brush size and strength can now be changed with the bracket keys, [ and ]

- Default resolution has been decreased to 1000x600
This should help slightly with the store page layout, and encourage more players to full-screen the game for more immersion (if desired) rather than the current somewhat awkward almost-full-screen embedded experience.